Amino Acids

 

Amino acids, the 'building blocks of life', form long chains called polypeptides or proteins, depending on their length.

Amino acids are classified by their different R groups, which vary in polarity and ionizability. There are 20 common amino acids that are found in mammalian cells, though others exist as well. Eight of these are essential amino acids, meaning we cannot synthesize them and depend on our diet to get them.

 

Our body requires 20 amino acids to form all the necessary body proteins. Nine amino acids are essential must be obtained from food. Our body can produce the other 11 from other molecules such as carbohydrates.

Essential Amino Acids

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

 

Non-Essential Amino Acids

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic acid
  • Cysteine
  • Glutamic acid
  • Glutamine
  • Glycine
  • Proline
  • Serine
  • Tyrosine

Some aa are considered “conditionally essential”. For example:

Thus, in a diet deficient in Phenylalanine and Methionine, Tyrosine and Cysteine will become essential.

 

 


Amino acids are composed of a central carbon bonded to four groups:
Amino group (NH2)
Acid group (COOH)
Hydrogen
R (a side group which determines the amino acid’s function, e.g. sulfur)